<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div{
            background-color: yellow;
            padding: 100px;
            width:100px;
            height: 100px;
            border:5px solid red;
            margin: 100px;
        }
    </style>
</head>
<body>
    <div>这是一个标签</div>
</body>
</html>